论文标题
分子转子以探测聚合物玻璃的局部粘度
Molecular rotors to probe the local viscosity of a polymer glass
论文作者
论文摘要
我们使用嵌入聚合物基质中的环境敏感的荧光分子转子来研究聚合物玻璃在其玻璃过渡温度周围的局部粘度。转子的荧光取决于局部粘度，因此测量了探针的荧光强度和寿命，因此可以在通过玻璃转变时测量聚合物玻璃中的局部游离体积。这也使我们能够研究局部粘度和自由体积时，当聚合物膜处于外部压力下。我们发现该胶片不是同质流动的，但是经历了剪切带，可见为空间变化的自由体积和粘度。
We investigate the local viscosity of a polymer glass around its glass transition temperature using environment-sensitive fluorescent molecular rotors embedded in the polymer matrix. The rotors' fluorescence depends on the local viscosity, and measuring the fluorescence intensity and lifetime of the probe therefore allows to measure the local free volume in the polymer glass when going through the glass transition. This also allows us to study the local viscosity and free volume when the polymer film is put under an external stress. We find that the film does not flow homogeneously, but undergoes shear banding that is visible as a spatially varying free volume and viscosity.
